Toro tiller broke rod and cracked crankcase

My Toro tiller went south. After 40 years of use. Took Good care of it.
However, what really caused this? I had a cub cadet 129 do the same thing.
Just wondering .

As 40 years go by the rods and mains just get bigger and bigger till they reach a point that tips them into self destruction. Jim

I would assume the rod stretched.

Is it a Kohler?

Briggs

Yes! and....(my theory)......
most small engines are splash lubricated, and as the rod wears
it flings the oil out faster than it can splash in.
Front tine tillers probably are a worst case scenario because they
thrash around so much when working. A ground driven rear tine is nite/day difference
in the thrashing. I'm surprised they even sell front tine still.

Yeah, apparently there are enough masochists out there that are too lazy to run a hoe...

(quoted from post at 07:06:43 07/14/17) Yes! and....(my theory)......
most small engines are splash lubricated, and as the rod wears
it flings the oil out faster than it can splash in.
Front tine tillers probably are a worst case scenario because they
thrash around so much when working. A ground driven rear tine is nite/day difference
in the thrashing. I'm surprised they even sell front tine still.

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When a guy wants to put in a small garden, it doesn't pay to buy a rear tine with what they cost for a 5x15 garden. I found an older front tine Gilson this year for $50. It's in great shape for it's age, and they even got it running for me the night before I came to pick it up. Hadn't run in 10 years.

Donovan from Wisconsin

For cost reasons, many small engine have some features that aren't best for life expectancy. The connecting rod will be subject to stress- but partially for cost reasons a aluminum connecting rod with no bearing insert will be used on plain journal, plash lubed with a 'dipping tab' on rod cap or a 'slinger on vertical shaft engines. Works long enough for warrantee and with oil changes quite a while afterwards - but as hotrodders found out years back a aluminum rod has stretch and 'egging' issues after use - and a no bearing insert to be replaced means potential disaster. Racers did replacement and rebuilds after so many miles or risked blowups/holes in side of blocks - small engine users don't do that with simple designs so eventually BOOM and smoke leaves engine so don't run no more- especially if oil is NOT changed regular. Some motorcycles used simple lube systems- but the ball and roller bearings meant lot longer life. Pressure lube systems last longer- but engine costs more and that means equipment has to be priced higher--which means customer has to be convinced it is worth extra cost and that means only commercial customers will pay for the units. Normal retail customer goes by price as main point after minimal usefulness. Steel connecting rod, cross drilled crank journal, replacable bearing insert or ball or roller bearing can get you fairly long life with simple lube system--look at old 2 strokes with crank setups and premixed with fuel lube. Lawnmower racers that have to use 'stock' engine blocks have made some improvements in lower ends so they can last a race with governors removed, 8000 rpm from 10 hp brigges engine base. Since some Brigges and Kohlers had ball bearing mains the connecting rod is the weak point to be improved- Hollowed crank pin with cross drill and a inserted bearing from Allis G or Continental 61 engine rod bearing fitted to slightly machined rod and bearing will get a Kohler another 1000 rpm with reasonable life expectancy. For $99.95 with coupon a Harbor Freight 212cc/6.5hp Predator can be used for some tiller replacements. RN

50 yrs ago, we were riding our mini-bikes. Guy with a 5hp B&S threw a rod thru the crankcase. He got some Devcon Plastic aluminum or steel, epoxy and built up the crankcase hole. Got another rod and he was out there again. Lasted at least the rest of the summer.

Do a work man like job, paint it; no one will know....LOL

(quoted from post at 17:25:50 07/14/17)
Do a work man like job, paint it; no one will know....LOL

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And if it don't look good, redneck it: put some more paint on it!

Excellent reply. 😊 thank you